CN115916437A - Coated cutting tool and cutting tool - Google Patents

Abstract

An undefined example of the present disclosure is a coated cutting tool having a substrate and a coating disposed on the substrate. The coated cutting tool includes a first surface, a second surface adjacent to the first surface, and a cutting edge located at least in part of a ridge portion between the first surface and the second surface. The coating has Al ₂ O ₃ A layer. The Al ₂ O ₃ Layer having said Al measured on the surface of said coating parallel to the surface of said substrate ₂ O ₃ The fracture toughness value of the layer is 5 MPa-m ^0.5 The above first region.

Description

Coated cutting tool and cutting tool

Cross reference to related applications

This application claims priority to japanese patent application No. 2020-112955, filed on 30/6/2020, and the disclosure of this prior application is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates to a coated cutting tool and a cutting tool having the same.

Background

Coated cutting tools for cutting tools and the like have a coating on a substrate. The coating is formed by CVD or PVD. An example of the coating layer formed by the CVD method includes a TiN layer, a TiCN layer, and Al layer sequentially stacked on a substrate ₂ O ₃ Coating of the layer.

A coating film formed by the CVD method sometimes has a large residual stress. In order to alleviate the residual stress, a measure is taken to project the ceramic particles toward the coating layer.

For example, japanese patent No. 4739235 (patent document 1) describes that a coat is subjected to sand blasting with ceramic abrasive grains.

Disclosure of Invention

An undefined example of the present disclosure is a coated cutting tool having a substrate and a coating disposed on the substrate. The coated cutting tool includes a first surface, a second surface adjacent to the first surface, and a cutting edge located at least in part of a ridge portion between the first surface and the second surface. The coating has Al ₂ O ₃ A layer. The Al ₂ O ₃ The layer has a fracture toughness value of 5 MPa-m when the fracture toughness value of the Al2O3 layer is measured on the surface of the coating layer parallel to the surface of the substrate ^0.5 The above first region.

Drawings

FIG. 1 is a perspective view of a coated cutting tool illustrating an undefined embodiment of the present disclosure.

Fig. 2 is a cross-sectional view of the section II-II in the coated cutting tool shown in fig. 1.

Fig. 3 is an enlarged view of the vicinity of the coating layer in the coated cutting tool shown in fig. 2.

Fig. 4 is an electron microscope (SEM) photograph of spherical ceramic particles.

Fig. 5 is an electron microscope (SEM) photograph of angular ceramic particles.

Fig. 6 is a perspective view of a cutting tool illustrating an undefined embodiment of the present disclosure.

Detailed Description

< coated cutting tool >

Hereinafter, the coated cutting tool 1 according to an embodiment of the present disclosure will be described in detail with reference to the drawings. However, in the drawings referred to below, for convenience of explanation, only main members necessary for explaining the embodiment are shown in a simplified manner. Thus, the coated cutting tool 1 can be provided with any constituent member not shown in the respective drawings to which reference is made. The dimensions of the members in the drawings do not faithfully represent the actual dimensions of the constituent members, the dimensional ratios of the members, and the like.

Fig. 1 to 3 show a cutting insert applicable to a cutting tool as an example of the coated tool 1. The coated cutting insert 1 can be applied to, for example, a sliding member, a wear-resistant member such as a die, a tool such as an excavating tool or a cutting edge, an impact-resistant member, and the like, in addition to a cutting insert. The use of the coated cutting tool 1 is not limited to the example.

The coated cutting tool 1 may also have a substrate 2 and a coating 3 on top of the substrate 2.

Examples of the material of the substrate 2 include cemented carbide, ceramics, and metals. Examples of cemented carbide include cemented carbide in which a hard phase composed of WC (tungsten carbide) and at least 1 kind selected from the group consisting of carbides, nitrides, and carbonitrides of metals of groups 4, 5, and 6 of the periodic table other than WC are bonded together with a binder phase composed of an iron metal such as Co (cobalt) and Ni (nickel). Other cemented carbides include Ti-based cermet and the like. As the ceramic, for example, si is mentioned ₃ N ₄ (silicon nitride), al ₂ O ₃ (alumina), diamond, and cBN (cubic boron nitride), and the like. Examples of the metal include carbon steel, high-speed steel, and alloy steel. The material of the substrate 2 is not limited to the exemplified material.

The coating 3 may cover the entire surface 4 of the substrate 2 or may cover only a part thereof. It can be said that the coating 3 is located on at least a portion of the substrate 2 when the coating 3 covers only a portion of the surface 4 of the substrate 2.

The coating 3 may be formed by Chemical Vapor Deposition (CVD). In other words, the coating 3 may be a CVD film.

The coating 3 is not limited to a specific thickness. For example, the thickness of the coating layer 3 may be set to 1 to 30 μm. The thickness and structure of the coating layer 3, the shape of the crystal constituting the coating layer 3, and the like can be measured by, for example, cross-sectional observation using an electron microscope. Examples of the electron microscope include a Scanning Electron Microscope (SEM) and a Transmission Electron Microscope (TEM).

As shown in fig. 1 and 2, the coated cutting tool 1 may include: a first surface 5 (upper surface), a second surface 6 (side surface) adjacent to the first surface 5, and a cutting edge 7 located at least in part of a ridge portion of the first surface 5 and the second surface 6.

The first surface 5 may be a rake surface. The first surface 5 may be a rake surface over the entire surface thereof or may be a rake surface partially. For example, the region along the cutting edge 7 in the first surface 5 may be a rake surface.

The second surface 6 may be a flank surface. The second surface 6 may be a flank surface over the entire surface thereof or may be a flank surface partially. For example, the region along the cutting edge 7 in the second surface 6 may be a flank surface.

The cutting edge 7 may be located at a part of the ridge line portion, or may be located at the entire ridge line portion. The cutting edge 7 can be used for cutting of the piece to be cut.

As shown in fig. 1, which is an example that is not limited, the coated cutting tool 1 may have a quadrangular plate shape. The shape of the coated cutting tool 1 is not limited to the shape of a rectangular plate. For example, the first face 5 may be triangular, pentagonal, hexagonal, or circular. In addition, the coated cutting tool 1 may have a cylindrical shape.

The coated cutting tool 1 is not limited to a specific size. For example, the length of one side of the first surface 5 may be set to about 3 to 20 mm. The height from the first surface 5 to the surface (lower surface) on the opposite side of the first surface 5 may be set to about 5 to 20 mm.

Here, as in the non-limited example shown in FIG. 3, the coating layer 3 may have Al ₂ O ₃ And (3) a layer 8.

Al ₂ O ₃ The layer 8 may also contain Al ₂ O ₃ A layer of particles. In addition, al ₂ O ₃ The layer 8 may also contain Al ₂ O ₃ As a layer of the main component. The term "main component" may mean a component having the largest mass% value as compared with other components. These points may be defined similarly in other layers as well.

Al ₂ O ₃ The layer 8 may also have a first region. The first region may have a fracture toughness value of 5MPa m ^0.5 The above. The fracture toughness value may be determined by measuring Al on the surface 9 of the coating 3 parallel to the surface 4 of the substrate 2 ₂ O ₃ The value in the case of the fracture toughness value of layer 8.

The above-mentioned "parallel" is not limited to strict parallel, and may mean that a tilt of about ± 10 ° is allowed. The fracture toughness value can also be measured by subjecting a mirror-finished surface to a indentation test using a nanoindenter and observing cracks in the resulting indentation using an electric field emission scanning electron microscope (FE-SEM). In the mirror polishing, a diamond polishing paste having an average particle diameter of 1 to 3 μm manufactured by tomeidiamond corporation and olive oil manufactured by shangui industrial corporation may be used so that the concentration of the polishing paste is adjusted to 20 to 30% by mass. The nanoindenter can be measured, for example, by using an ultramicro indentation hardness tester ENT-1100b/a manufactured by ELIONIX. As an indenter used for the measurement, a glass indenter ENT-20-13 manufactured by toyo-technica, inc. was used, and the indentation load was 700 (mN). The fracture toughness value may be measured in accordance with JIS R1607: 2015 as a reference. The cracks were observed by using JSM-7100F manufactured by Nippon electronic Co., ltd.

In Al ₂ O ₃ When the layer 8 has the first region, the coating layer 3 is less likely to be damaged, and therefore, is excellent in defect resistance. It may be Al ₂ O ₃ All of layer 8 is defined by the first zoneThe domain structure may be Al ₂ O ₃ A part of the layer 8 is constituted by the first region. Hereinafter, the fracture toughness value of the first region is referred to as a first fracture toughness value. The upper limit of the first fracture toughness value may be 10MPa · m ^0.5 。

Al ₂ O ₃ The layer 8 may have the first region on each of the first surface 5 and the second surface 6. In this case, the first surface 5 and the second surface 6 are hardly damaged.

Al ₂ O ₃ The layer 8 may also have a second region. Al in coated tool 1 ₂ O ₃ The layer 8 need not have high fracture toughness over the entire area. For example, the second region is disposed in a region not involved in cutting, or a region not subjected to a large force or impact even in a region involved in cutting. The region not involved in cutting may be a region separated by 1mm or more from the cutting edge 7 in the direction of the first surface 5 and the second surface 6. The second region may have a fracture toughness value of less than 5MPa · m ^0.5 . The fracture toughness value may be determined by measuring Al on the surface 9 of the coating 3 parallel to the surface 4 of the substrate 2 ₂ O ₃ The value in the case of the fracture toughness value of layer 8.

The first region of the present disclosure is obtained, for example, by a sand blasting process using spherical ceramic powder having a predetermined hardness. In the blasting step, so-called dry blasting or wet blasting may be used. Wet blasting has the advantage of being excellent in handling of the ceramic powder.

In the presence of Al ₂ O ₃ Even when the layer 8 has the first region and the second region, the time required for the blasting step can be shortened, and the coated cutting tool 1 can be manufactured at low cost. Hereinafter, the fracture toughness value of the second region is referred to as a second fracture toughness value. The lower limit of the second fracture toughness value may be 0.3MPa · m ^0.5 。

When the hardness of the first region is set to the first hardness and the hardness of the second region is set to the second hardness, the second hardness may be higher than the first hardness. In this case, the coated cutting tool 1 has high wear resistance.

The first hardness and the second hardness are not limited to specific values. For example, the first hardness may be set to about 10 to 30 GPa. The second hardness may be set to about 15 to 30 GPa. The first hardness and the second hardness may be, for example, al ₂ O ₃ The fracture toughness value of the layer 8 was measured by the indentation test using a nanoindenter in the same manner. The nanoindenter can be measured, for example, by using an ultramicro indentation hardness tester ENT-1100b/a manufactured by ELIONIX. As an indenter used for the measurement, a glass indenter ENT-20-13 manufactured by toyo-technica may be used with an indentation load of 700 (mN).

Al ₂ O ₃ The layer 8 may have a first region on the first surface 5, or may have a second region on the second surface 6. In this case, the coated cutting tool 1 has high wear resistance and high chipping resistance.

The coating 3 may also be formed on the substrate 2 with Al ₂ O ₃ Between the layers 8, there is a Ti based coating 10. The Ti-based coating 10 may be a layer containing TiCN particles, tiC particles, or TiN particles. The Ti-based coating 10 may contain TiCN as a main component.

The Ti-based coating 10 may have a third region. The third region may have a fracture toughness value of 10 MPa-m ^0.5 As described above. The fracture toughness value may be a value obtained by measuring the fracture toughness value of the Ti-based coating 10 on the surface 9 of the coating 3 parallel to the surface 4 of the substrate 2.

When the Ti-based coating 10 has the third region, the coating 3 is less likely to be damaged, and thus is excellent in defect resistance. The entire Ti-based coating 10 may be formed of the third region, or a part of the Ti-based coating 10 may be formed of the third region. Hereinafter, the fracture toughness value of the third region will be referred to as a third fracture toughness value. The upper limit of the third fracture toughness value may be 20MPa · m ^0.5 。

The Ti-based coating 10 may have a fourth region. The Ti-based coating 10 of the coated cutting tool 1 does not need to have high fracture toughness in all regions. For example,the fourth region may be disposed in a region not involved in cutting, or in a region not involved in cutting and not subjected to a large force or impact. The region not involved in cutting may be a region separated by 1mm or more from the cutting edge 7 in the direction of the first surface 5 and the second surface 6. The fourth region may have a fracture toughness value of less than 10MPa · m ^0.5 . The fracture toughness value may be a value obtained by measuring the fracture toughness value of the Ti-based coating 10 on the surface 9 of the coating 3 parallel to the surface 4 of the substrate 2.

The third region of the present disclosure is obtained, for example, by a sand blast process using spherical ceramic powder having a predetermined hardness. In the blasting step, so-called dry blasting or wet blasting may be used. Wet blasting has the advantage of being excellent in handling of the ceramic powder.

Even when the Ti-based coating 10 has the third region and the fourth region, the time of the blasting step can be shortened, and the coated cutting tool 1 can be manufactured at low cost. Hereinafter, the fracture toughness value of the fourth region is referred to as a fourth fracture toughness value. The lower limit of the fourth fracture toughness value may be 1.5MPa · m ^0.5 。

When the hardness of the third region is set to the third hardness and the hardness of the fourth region is set to the fourth hardness, the third hardness may be higher than the fourth hardness. In this case, the coated cutting tool 1 has high wear resistance.

The third hardness and the fourth hardness are not limited to specific values. For example, the third hardness may be set to about 15 to 30 GPa. The fourth hardness may be set to about 10 to 30 GPa. The third hardness and the fourth hardness may be measured in the same manner as the first hardness and the second hardness.

The first region may be located above the third region, and the second region may be located above the fourth region. In this case, the chipping resistance is high, the time of the blasting process can be shortened, and the coated cutting tool 1 can be manufactured at low cost.

Al ₂ O ₃ Layer 8 may be (104) in X-ray diffraction) The half width of the surface is 0.15 DEG or more. In this case, the coating layer 3 is less likely to be defective and is excellent in defect resistance. Al (Al) ₂ O ₃ The half-value width of the (104) surface of the layer 8 may be measured as follows. (104) The faces may also be referenced to JCPDS card numbers 00-010-0173. In the presence of Al ₂ O ₃ When the layer 8 is exposed by wet blasting, the exposed Al may be ₂ O ₃ The surface of layer 8 was mirror-polished to obtain a mirror surface, and XRD measurement was performed. In Al ₂ O ₃ When the layer 8 is not exposed, the mirror polishing treatment may be continued until Al is formed ₂ O ₃ Until layer 8 is exposed, in Al ₂ O ₃ The exposed mirror surface of layer 8 was subjected to XRD measurement. Al (aluminum) ₂ O ₃ XRD measurement of the layer 8 can be performed by selecting a surface having few irregularities on the surface. The XRD measurement can be performed by using MiniFlex600 manufactured by Rigaku corporation. The measurement conditions may be set such that the characteristic X-ray is CuK β line, the output is 40kV and 15mA, the transmission-side soller slit is 2.5 °, the length-limiting slit is 5.0mm, the diffusion slit is 0.625 °, the scattering slit is 8.0mm, the light-receiving-side soller slit is 2.5 °, the light-receiving slit is 13.0mm, the step size is 0.01 °, the measurement speed is 2.0 °/min, and the scanning angle is 20 ° to 90 °. In addition, al is ₂ O ₃ The upper limit of the half-value width of the (104) plane of the layer 8 may be 2.0 °.

The coating 3 may also comprise Al ₂ O ₃ A layer 8 and a layer other than the Ti based coating 10. Examples of the other layer include a TiC layer and a TiN layer. As an unconfined example shown in FIG. 3, the coating layer 3 may be formed by sequentially laminating a TiN layer 11, a Ti-based coating layer 10, and Al on the substrate 2 ₂ O ₃ Layer 8 may be formed of Al ₂ O ₃ A TiN layer 12 and the like are stacked on the layer 8. Al (Al) ₂ O ₃ The layer 8 may be in contact with a Ti-based coating 10. For convenience, the TiN layer 11 may be referred to as a first TiN layer 11, and the TiN layer 12 may be referred to as a second TiN layer 12.

A first TiN layer 11, a Ti-based coating 10, al ₂ O ₃ The thickness of each of the layer 8 and the second TiN layer 12The degree is not limited to a specific value. For example, the thickness of the first TiN layer 11 may be set to 0.1 to 3.0 μm. The thickness of the Ti based coating 10 may be set to 1.0 to 20 μm. Al (aluminum) ₂ O ₃ The thickness of the layer 8 may be set to 1.0 to 20 μm. The thickness of the second TiN layer 12 may be set to 0.1 to 10 μm.

The coating cutter 1 may also have a through hole 13. The through-hole 13 can be used for attaching a fixing screw, a clamping member, or the like when the coated cutting tool 1 is held by the holder. The through-hole 13 may be formed from the first surface 5 to a surface (lower surface) located on the opposite side of the first surface 5, or may be open on these surfaces. The through-hole 13 has no problem even in a structure in which the regions of the second surface 6 that face each other are open.

< method for producing coated cutting tool >

Next, a method for manufacturing a coated cutting tool according to an embodiment of the present disclosure will be described by taking a case of manufacturing the coated cutting tool 1 as an example.

The substrate 2 may also be initially manufactured. The substrate 2 will be described by taking an example of a case where the substrate 2 made of cemented carbide is manufactured. First, a mixed powder may be obtained by adding and mixing a metal powder, a carbon powder, or the like to an inorganic powder such as a metal carbide, a nitride, a carbonitride, or an oxide that can form the matrix 2 by firing as appropriate. Next, the mixed powder may be molded into a predetermined tool shape by a known molding method such as press molding, cast molding, extrusion molding, and cold isostatic pressing to obtain a molded body. Then, the obtained molded body may be fired in a vacuum or in a non-oxidizing atmosphere to obtain the base body 2. The surface 4 of the base 2 may be subjected to grinding or honing.

Next, the coating layer 3 may be formed on the surface 4 of the obtained substrate 2 by CVD. Further, the wet blasting may be performed on the coating layer 3 formed as a film. Hereinafter, the coated tool 3 and the coated tool 1 before wet blasting are referred to as an untreated coated tool and an untreated coated tool. Further, the untreated coating layer on which the wet blasting treatment has been performed is referred to as a coating layer 3, and the untreated coated tool is referred to as a coated tool 1. The process before the wet blasting is performed may also be referred to as a first process of preparing an untreated coated tool having an untreated coating on the substrate 2.

As the untreated coating, for example, a first TiN layer 11, a Ti based coating 10, and Al may be formed in this order on the substrate 2 ₂ O ₃ Layer 8. Further, al may be added ₂ O ₃ A second TiN layer 12 and the like are formed on the layer 8.

The first TiN layer 11 may be formed as follows. First, titanium tetrachloride (TiCl) contained in an amount of 0.1 to 10 vol% may be adjusted as the reaction gas composition ₄ ) Gas, nitrogen (N) contained in an amount of 10 to 60 vol% ₂ ) Gas, remainder hydrogen (H) ₂ ) A mixed gas composed of gases. Then, the first TiN layer 11 may be formed by introducing the mixed gas into the chamber, setting the temperature to 800 to 1010 ℃, and the pressure to 10 to 85 kPa. The film formation conditions can also be applied to the second TiN layer 12.

The Ti-based coating 10 may be formed as follows. First, titanium tetrachloride (TiCl) contained in an amount of 0.1 to 10 vol% may be adjusted as the reaction gas composition ₄ ) Gas, acetonitrile (CH) contained in an amount of 0.1 to 3.0 vol% ₃ CN) gas, remainder hydrogen (H) ₂ ) A mixed gas composed of gases. Then, the Ti-based coating 10 may be formed by introducing the mixed gas into the chamber, setting the temperature to 800 to 1050 ℃, and the pressure to 5 to 30 kPa.

Al ₂ O ₃ The layer 8 may be formed as follows. First, the composition of the reaction gas may be adjusted to 0.5 to 5 vol% of aluminum trichloride (AlCl) ₃ ) A gas, hydrogen chloride (HCl) gas contained in an amount of 0.5 to 3.5 vol%, and carbon dioxide (CO) contained in an amount of 0.5 to 5 vol% ₂ ) A gas, a hydrogen sulfide (H2S) gas contained in an amount of 0.5% by volume or less, and the balance being a mixed gas of a hydrogen (H2) gas. Then, the mixed gas may be introduced into the chamber andthe temperature is 930 to 1010 ℃, the pressure is 5 to 10kPa, and Al is added ₂ O ₃ Layer 8 is formed.

Next, a step of performing wet blasting on the untreated coating layer formed may be performed. This step may be a second step of colliding spherical ceramic particles having a Hardness (HV) of 1000 or more with the untreated coating. HV (Vickers hardness: vickers hardness) may be measured in accordance with JIS Z2244: 2009 as a standard. The upper limit of the Hardness (HV) of the spherical ceramic particles may be 2500.

The hardness of a medium such as spherical ceramic particles can also be measured by hardness measurement based on a load-divided load test. In the measurement of the hardness, a cured body obtained by mixing a medium and an embedding resin and then curing the mixture may be used. The hardness of the medium exposed on the polished surface of the cured product by polishing may be measured. For example, technovit4004 manufactured by Kulzer may be used as the embedding resin. The medium to be measured and the embedding resin may be mixed in a ratio of 3:1 (mass ratio) was mixed to prepare a cured product, and the surface was polished. After polishing, the hardness of the exposed medium portion of the cured product may be measured. The measurement can also be performed by using a dynamic ultramicro hardness tester DUH-211S. The measurement may be performed under the conditions that the measurement indenter is a triangular pyramid indenter (made of diamond) with an angular separation of 115 °, the test force is 49 (mN), the load speed is 2.665 (mN/sec), and the holding time is 5 seconds. The number of measurements may be 10, and the average value may be measured.

The second step may be performed on the entire surface of the untreated coating layer, or may be performed on a part thereof. The part of the untreated coating subjected to the second step easily makes Al ₂ O ₃ The layer 8 has a first region, and the Ti-based coating 10 easily has a third region. Al is easily caused in the part of the untreated coating layer not subjected to the second step ₂ O ₃ The layer 8 has a second region, and the Ti-based coating 10 easily has a fourth region.

In the wet blasting treatment, a blasting liquid containing spherical ceramic particles in a liquid may also be projected onto the untreated coating. The blasting liquid is also referred to as a slurry. For example, water may be used as the liquid.

The term "spherical ceramic particles" may mean particles obtained by pulverizing a raw material. In order to distinguish from spherical ceramic particles, ceramic particles obtained by pulverizing a raw material may be referred to as angular ceramic particles. Fig. 4 shows a photograph of the spherical ceramic particles. Fig. 5 shows a photograph of angular ceramic particles. The density of the spherical ceramic particles may be 6g/cm ³ The following. The density is 6g/em ³ The following spherical ceramic particles are relatively low in density and therefore easily dispersed in water, and are suitable for wet blasting. For example, al ₂ O ₃ The density of the particles is about 4g/cm ³ 。

As shown in the photograph of fig. 5, the angular ceramic particles may have an irregular shape. The angular ceramic particles may be ceramic particles produced by pulverizing raw material particles or the like, or ceramic particles having a pulverization surface and an angle formed by pulverizing process powder. Angular ceramic particles have been used in conventional wet blasting.

On the other hand, as shown in the photograph of fig. 4, the spherical ceramic particles may have a shape close to a regular sphere without any angle. The shape of the spherical ceramic particles is not necessarily a regular sphere, and deformation from a sphere can be somewhat tolerated as long as there is no grinding surface or acute angle.

The particles having a shape similar to that of the spherical ceramic particles include spherical metal particles. The spherical metal particles are similar in shape to the spherical ceramic particles, but have a higher density and are softer than the spherical ceramic particles. For example, the spherical metal particles have a density of 7 to 8g/cm ³ . In addition, the Hardness (HV) of the spherical metal particles is less than 1000. It is presumed that such characteristics are caused, but when spherical metal particles are used, it is difficult to obtain the coated cutting tool 1 having the first region and the third region. In addition, spherical metal particles are difficult to disperse in water due to their high density, and are not suitable for wet blasting.

For the same reason, even in the case of spherical ceramic particles, if glass beads or glass components having a Hardness (HV) of less than 1000 are contained in a large amount, it is difficult to obtain the coated cutting tool 1 having the first region and the third region.

In the wet blasting treatment, spherical ceramic particles of various sizes can be used. When spherical ceramic particles having a large average particle diameter are used, the blasting time is easily shortened. The average particle diameter of the spherical ceramic particles may be 200 μm or less.

The average particle diameter of the spherical ceramic particles may be 30 μm or more and 100 μm or less. When spherical ceramic particles in this range are used, various untreated coatings can be sandblasted with good reproducibility.

The average particle diameter of the spherical ceramic particles can also be measured by a laser diffraction method. When the spherical ceramic particles and the angular ceramic particles are mixed, the blasting liquid may be dried, and the spherical ceramic particles may be extracted by SEM photograph as an average value of the equivalent circle diameters of 100 spherical ceramic particles obtained from the photograph.

The average circularity of the spherical ceramic particles may be 0.82 or more. In particular, the average circularity of the spherical ceramic particles may be 0.88 or more. In this case, the manufactured coated cutting tool has high chipping resistance. The upper limit of the average circularity may be 0.98.

The average circularity is measured as follows. First, after the particle image is captured by SEM or TEM, the projected area (S) and the peripheral length (L) of the particle may be measured by using image analysis software (for example, "Mac-viewversion.4" manufactured by mountech). Next, the obtained measurement value may be applied to the formula: 4 π S/L2 to calculate circularity. The circularity can be calculated for 100 particles arbitrarily selected, and the average value thereof is taken as the average circularity.

As the material of the spherical ceramic particles, for example, al is cited ₂ O ₃ 、ZrO ₂ And SiC and the like. In addition, even when spherical ceramic particles made of a material having a high density are used, the ceramic particles are likely to be dispersed in a liquidThe average particle diameter can be made small. When spherical ceramic particles made of a material having a low density are used, the average particle diameter may be increased.

The blasting liquid may be prepared by adding 10 to 40 vol% of spherical ceramic particles to water.

The projection pressure of the blasting liquid may be 0.15 to 0.30MPa and the projection time may be 0.4 to 10.0 seconds. When the projection time of the blasting liquid exceeds 10.0 seconds, peeling of the untreated coating layer tends to increase, and therefore, this is not suitable. In addition, al may be used when the blasting liquid is applied to the untreated coating ₂ O ₃ At least a portion of layer 8 remains.

For example, the coated cutting tool 1 can be manufactured by the above-described steps.

The ceramic particles may contain a part of the horn-like shape of the blasting liquid. In that case, 50% by volume or more of the ceramic particles may be spherical ceramic particles.

The blasting liquid containing angular ceramic particles may be projected before the blasting liquid containing spherical ceramic particles is projected. Further, after the blasting liquid containing spherical ceramic particles is projected, the blasting liquid containing angular ceramic particles may be projected. By projecting the blasting liquid containing the spherical ceramic particles, the fracture toughness value of the coating layer 3 becomes high, and it becomes difficult to lower the value even if the blasting liquid containing the angular ceramic particles is projected.

When the blasting liquid containing spherical ceramic particles is projected onto the untreated coating layer, for example, a commercially available wet blasting apparatus may be used.

In untreated coated tools, the untreated coating may also have tensile stress. The tensile stress is not limited to a specific value. The absolute value of the tensile stress may be set to about 50 to 500 MPa.

The untreated coating may also have a compressive stress. The compressive stress is not limited to a specific value. The absolute value of the compressive stress may be set to about 50 to 2000 MPa.

The tensile stress and the compressive stress can be measured by a sin2 ψ method using an X-ray stress measuring apparatus (XRD). In the measurement of residual stress, al is ₂ O ₃ The layer 8 may also be made of alpha-Al ₂ O ₃ Is measured on the (116) plane. The Ti based coating 10 can be measured by selecting the (422) surface of TiCN.

In the resulting coated cutting tool 1, a region including the cutting edge 7 may be subjected to a grinding process. This smoothes the region including the cutting edge 7. As a result, welding of the workpiece is suppressed, and the cutting edge 7 has high chipping resistance.

The above-described manufacturing method is an example of a method for manufacturing the coated cutting tool 1. Therefore, it is needless to say that the coated cutting tool 1 is not limited to the coated cutting tool manufactured by the above-described manufacturing method.

< cutting tool >

Next, the cutting tool 101 according to an embodiment of the present disclosure, which is not limited to the above, will be described in detail with reference to fig. 6, taking the case of the coated tool 1 as an example.

As an example shown in fig. 6, which is not limited, the cutting insert 101 may have: a shank 102 having a length from a first end 102a to a second end 102b and having a pocket 103 on one side of the first end 102 a; and a coating cutter 1 located in the pocket 103. When the cutting tool 101 has the coated tool 1, the coated tool 1 is excellent in chipping resistance, and therefore stable cutting can be performed for a long period of time.

The pocket 103 may also be a portion for mounting the coated cutting tool 1. The pocket 103 may be open on the outer peripheral surface of the holder 102 and an end surface on the first end 102a side.

The coated cutting insert 1 may be attached to the pocket 103 so that the cutting edge 7 protrudes outward from the shank 102. In addition, the coating cutter 1 may be attached to the pocket 103 by a fixing screw 104. That is, the coated tool 1 may be attached to the pocket 103 by inserting the fixing screw 104 into the through hole 13 of the coated tool 1, inserting the tip of the fixing screw 104 into a screw hole formed in the pocket 103, and screwing the screw portions together. A sheet material may be sandwiched between the coating cutter 1 and the knife groove 103.

Examples of the material of shank 102 include steel and cast iron. When the material of the shank 102 is steel, the shank 102 has high toughness.

In an example shown in fig. 6, a cutting tool 101 used for so-called turning is exemplified. Examples of the turning include inner diameter machining, outer diameter machining, and grooving. The use of the cutting insert 101 is not limited to turning. For example, there is no problem even if the cutting tool 101 is used for turning.

The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to the following examples.

[ examples ] A method for producing a compound

[ sample Nos. 1 to 11]

< preparation of coated cutting tool >

First, a substrate is produced. Specifically, a WC powder having an average particle diameter of 1.2 μm was mixed with a metallic Co powder having an average particle diameter of 1.5 μm at a ratio of 6 mass%, a TiC (titanium carbide) powder at a ratio of 2.0 mass%, and a Cr powder at a ratio of 0.2 mass% ₃ C ₂ (chromium carbide) powder, and a mixed raw material powder was prepared. Next, the mixed raw material powder was press-molded into a cutting tool shape (CNMG 120408), and a molded body was obtained. The obtained compact is subjected to binder removal treatment and fired at 1400 ℃ for 1 hour in a vacuum of 0.5 to 100Pa to produce a base made of cemented carbide. A cutting edge treatment (R honing) was performed on one side of the rake face (first face) of the produced substrate by brushing.

Next, an untreated coating is formed on the substrate. Specifically, a first TiN layer, a Ti-based coating layer, and Al are sequentially formed on a substrate from one side of the substrate ₂ O ₃ Layer, second TiN layer. The film formation conditions and thickness were as follows. The thickness is a value obtained by cross-sectional measurement by SEM.

(first TiN layer)

TiCl ₄ Gas: 1.0% by volume

N ₂ Gas: 55.0% by volume

H ₂ Gas: the remaining part

Temperature: 850 deg.C

Pressure: 16kPa

Thickness: 1.0 μm

(Ti-based coating)

TiCl ₄ Gas: 7.0% by volume

CH ₃ CN gas: 0.5% by volume

H ₂ Gas: the remaining part

Temperature: 850 deg.C

Pressure: 10kPa

Thickness: 7.0 μm

(Al ₂ O ₃ Layer)

AlCl ₃ Gas: 4.2% by volume

HCl gas: 0.9% by volume

CO ₂ Gas: 4.5% by volume

H ₂ S gas: 0.3% by volume

H ₂ Gas: the remaining part

Temperature: 950 ℃ C

Pressure: 9kPa

Thickness: 8.0 μm

(second TiN layer)

TiCl ₄ Gas: 3.0% by volume

N ₂ Gas: 40.0% by volume

H ₂ Gas: the remaining part

Temperature: 1010 deg.C

Pressure: 30kPa

Thickness: 2.0 μm

Next, as a medium, 25% by volume of spherical Al having an average particle diameter shown in Table 1 was contained in each case based on water ₂ O ₃ Particles, zircon (ZrSiO) ₄ ) Spherical particles and angular Al ₂ O ₃ The sand blasting liquid is adjusted by the particle mode. The Hardness (HV) of the medium was measured as follows.

(Medium hardness)

The hardness of the medium used for the blast treatment was measured by hardness measurement based on a load-unload test. First, a medium to be measured was fixed with an embedding resin (Technovit 4004 manufactured by Kulzer) and the surface was polished. Specifically, 3gAl was added to 1g of a resin obtained by mixing a liquid curable resin and a curing agent at a mass ratio of 3:1 ₂ O ₃ The powders were mixed and then cured at room temperature (23 ℃) for about 1 hour to obtain a cured product. Thereafter, the procedure of grinding the solidified body was used. After the polishing, the hardness of the exposed medium portion of the cured product was measured. The measurement was carried out using a dynamic ultramicro-hardness tester DUH-211S. The measurement was performed under the conditions that the measurement indenter was an inter-edge angle of 115 °, the triangular pyramid indenter (made of diamond), the test force was 49 (mN), the load speed was 2.665 (mN/sec), and the holding time was 5 seconds. The number of measurements was 10 times, and the average value thereof was measured.

The adjusted blasting liquid was projected onto the untreated coating layer at a pressure of compressed air (projection pressure) set to 0.2MPa and for the time shown in table 1, and a coated cutting tool was obtained. The blasting liquid projects the areas of the first surface and the second surface that are to be cut. The cutting region is a region of less than 1mm in a direction from the cutting edge toward the first surface and the second surface.

Very good (Table 1)

< evaluation >

With respect to the obtained coated cutting tools, first to fourth fracture toughness values and first to fourth hardnesses were measured. In addition, the half-value width of the (104) plane of the region involved in cutting was measured. The obtained coated cutting tools were used for cutting evaluation, and the chipping resistance was evaluated. The measurement methods are shown below, and the results are shown in tables 2 and 3.

(first to fourth fracture toughness values)

The mirror-finished surface was subjected to a press-in test using a nanoindenter, and the obtained indentation was observed for cracks using an electric field emission scanning electron microscope (FE-SEM), and the fracture toughness value was measured. The measurement was performed using an ultra-fine indentation hardness tester ENT-1100b/a manufactured by ELION, inc. as a nanoindenter. The indentation load was 700 (mN), and the indenter used for the measurement was measured using a glass indenter ENT-20-13 manufactured by toyo-technica. Fracture toughness values are as defined in JIS R1607: measurement was performed with 2015 as a reference. The cracks were observed using JSM-7100F manufactured by Nippon electronics Co.

In the presence of Al ₂ O ₃ When the layer is exposed by wet blasting, the exposed Al is ₂ O ₃ The fracture toughness value was measured on a mirror surface obtained by mirror-polishing the surface of the layer. In the presence of Al ₂ O ₃ When the layer is not exposed, the mirror polishing treatment is continued until Al is formed ₂ O ₃ Until the layer is exposed at Al ₂ O ₃ The exposed mirror surface of the layer measured the fracture toughness value.

The fracture toughness value of the Ti-based coating layer was also obtained by performing mirror polishing until the Ti-based coating layer was exposed from the surface of the coating layer and measuring the mirror surface of the exposed Ti-based coating layer.

In the mirror polishing, a diamond polishing paste having an average particle diameter of 1.4 μm manufactured by tomeidiamond corporation and olive oil manufactured by shangui industrial corporation were used, and the concentration of the polishing paste was adjusted to 25 mass%. The mirror polishing is performed so that the mirror surface is parallel to the surface of the substrate.

(first to fourth hardness)

The measurement was performed by a press-in test using a nanoindenter. As the nanoindenter, an ultramicro indentation hardness tester ENT-1100b/a manufactured by ELIONIX was used. An indenter used for the measurement was a glass indenter ENT-20-13 manufactured by toyo-technica, inc., having an indentation load of 700 (mN).

(half-value Width of (104) plane of the region relating to cutting)

The half-value width of the (104) plane of the region relating to cutting of the surface subjected to wet blasting was measured. Al (Al) ₂ O ₃ The (104) side of the layer is referenced to JCPDS card number 00-010-0173. In Al ₂ O ₃ When the layer is exposed by wet blasting, the exposed Al is ₂ O ₃ The surface of the layer was mirror-polished to obtain a mirror surface, and XRD measurement was performed. In Al ₂ O ₃ When the layer is not exposed, mirror polishing is continued until Al is formed ₂ O ₃ Until the layer is exposed at Al ₂ O ₃ The exposed mirror surface of the layer was measured by XRD. Al (Al) ₂ O ₃ XRD measurement of the layer was performed by selecting a surface having few irregularities on the surface. XRD measurement was performed using MiniFlex600 manufactured by Rigaku corporation. The measurement conditions may be performed by setting the characteristic X-ray to CuK β ray, the output to 40kV and 15mA, the transmission-side soller slit to 2.5 °, the length-limiting slit to 5.0mm, the diffusion slit to 0.625 °, the scattering slit to 8.0mm, the light-receiving-side soller slit to 2.5 °, the light-receiving slit to 13.0mm, the step size to 0.01 °, the measurement speed to 2.0 °/minute, and the scanning angle to 20 ° to 90 °.

(evaluation of cutting)

The interrupted cutting test was performed under the following conditions.

A workpiece to be cut: carbon steel for machine structure (S45C steel with 16 grooves)

Tool shape: CNMG120408

Cutting speed: 48 m/min

Conveying speed: 0.27mm/rev

Cutting in: 1.0mm

And others: using water-soluble cutting fluids

Evaluation items: measuring the number of impacts to the defect

Very good (Table 2)

Very good (Table 3)

Sample No.1 was not treated with the untreated coating projection blasting liquid. In other words, sample No.1 is a coated cutting tool in which only a coating layer is formed on a substrate. Al in sample No.1 ₂ O ₃ The first and second surfaces of the layer having a fracture toughness value of 0.8MPa m ^0.5 。

Sample No.2 was shot with blasting solution containing angular ceramic particles onto the first and second surfaces. In sample No.2, al ₂ O ₃ The fracture toughness value of the layer was slightly higher than that of sample No.1 without treatment, and both the first surface and the second surface were 1.5MPa · m ^0.5 。

Samples No.3 and 4 will contain spherical zircon (ZrSiO) ₄ ) The blasting liquid of the particles is projected to the first surface and the second surface. In samples No.3 and 4, al ₂ O ₃ The fracture toughness value of the layer was slightly higher than that of sample No.1 without treatment, and both the first surface and the second surface were 1.5MPa · m ^0.5 Or 2.0 MPa.m ^0.5 。

Al of samples Nos. 1 to 4 ₂ O ₃ The fracture toughness values of the layers are all low values.

In contrast, al as samples No.5 to 11 of the coated cutting tool of the present disclosure ₂ O ₃ The layer has a fracture toughness value of 5.0MPa m ^0.5 Above or 6.5 MPa.m ^0.5 The region (2) is excellent in defect resistance.

The spherical Al in samples Nos. 5 to 11 ₂ O ₃ Angular Al in particles and sample No.2 ₂ O ₃ Particles, average circularity was measured. Specifically, first, after the particle image was captured by SEM, the projected area (S) and the peripheral length (L) of the particles were measured using image analysis software ("Mac-viewversion.4" manufactured by mountech). Then, theThe obtained measurement value is applied to the formula: 4 π S/L2 to calculate circularity. The circularity is calculated for arbitrarily selected 100 particles, and the average value thereof is taken as the average circularity. The measurement results of the average circularity are as follows.

(average circularity)

Spherical Al in sample Nos. 5 to 11 ₂ O ₃ Particle: 0.90

Angular Al in sample No.2 ₂ O ₃ Particle: 0.74

Description of the reference numerals

1. Coating cutter

2. Base

3. Coating

4. Surface

5. First face

6. Second face

7. Cutting edge

8···Al ₂ O ₃ Layer(s)

9. Surface

10.Ti series coating

11. TiN layer (first TiN layer)

12. TiN layer (second TiN layer)

13. Through hole

101. Cutting tool

102. Knife handle

102 a. First terminal

102 b. Second terminal

103. Knife slot

104. Set screw.

Claims (9)

1. A coated cutting tool having a substrate and a coating on the substrate,

the coated cutting tool is provided with: a first side; a second face adjacent to the first face; and a cutting edge located on at least a part of the ridge portion of the first surface and the second surface,

the coating has Al ₂ O ₃ A layer of a polymer,

the Al ₂ O ₃ Layer having said Al measured on the surface of said coating parallel to the surface of said substrate ₂ O ₃ The fracture toughness value of the layer is 5 MPa-m ^0.5 The above first region.

2. The coated cutting tool of claim 1,

the Al is ₂ O ₃ The layer has the first region on the first side and the second side, respectively.

3. The coated cutting tool of claim 1,

the Al is ₂ O ₃ Layer having said Al measured on the surface of said coating parallel to the surface of said substrate ₂ O ₃ The fracture toughness value of the layer is less than 5MPa m ^0.5 And a second region having a hardness greater than the first hardness when the hardness of the first region is set to a first hardness and the hardness of the second region is set to a second hardness.

4. The coated cutting tool of claim 3,

the Al is ₂ O ₃ A layer has the first region on the first side and the second region on the second side.

5. The coated cutting tool according to any one of claims 1 to 4,

the coating is formed on the substrate and the Al ₂ O ₃ A Ti-based coating layer is provided between the layers,

the Ti-based coating layer has a fracture toughness value of 10 MPa-m when the fracture toughness value of the Ti-based coating layer is measured on the surface of the coating layer parallel to the surface of the substrate ^0.5 The above third area.

6. The coated cutting tool of claim 5,

the Ti-based coating has a fracture toughness value of less than 10 MPa-m when the fracture toughness value of the Ti-based coating is measured on the surface of the coating parallel to the surface of the substrate ^0.5 And a fourth region having a hardness of a third hardness and a hardness of a fourth region having a hardness of a fourth hardness, wherein the third hardness is higher than the fourth hardness.

7. The coated cutting tool of claim 6,

the Al is ₂ O ₃ Layer having said Al measured on the surface of said coating parallel to the surface of said substrate ₂ O ₃ The fracture toughness value of the layer is less than 5MPa m ^0.5 And the first region is located above the third region, and the second region is located above the fourth region.

8. The coated cutting tool according to any one of claims 1 to 7,

the Al is ₂ O ₃ The half-value width of the (104) plane in X-ray diffraction is 0.15 DEG or more.

9. A cutting tool, wherein,

the cutting tool has:

a shank having a length from a first end to a second end and having a pocket on a side of the first end; and

the coated cutting tool of any of claims 1-8, located in the pocket.

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